The present invention relates to a cooling tower having circumferentially distributed inlet openings at the lower end for the entrance of cooling air and a central upper outlet opening, through which cooling air flows, on the one hand, countercurrently to a medium to be cooled with flows in downward direction over a trickling unit (wet cooling section), and on the other hand, parallel thereto about heat-exchanger elements, flown through by a medium to be cooled (dry cooling section), and in which the trickling unit and the heat-exchanger elements are separated from each other.
In a known cooling tower construction of the aforementioned kind, the wet cooling section and the dry cooling section are divided in a plurality of V-shaped sectors, as considered in horizontal cross section of the cooling tower, with the sectors of the wet cooling section alternating with those of the dry cooling section in circumferential direction of the tower. Separating walls between the alternating, successive sectors of the wet cooling section and the dry cooling section create passages, which diminish in cross section toward the central axis of the tower, through which the cooling air passes. Each sector of the wet cooling section is provided with a radially extending main channel and with normally thereto arranged auxiliary channels from which the medium to be cooled, in this case water, flows through openings in the bottom of the channels downwardly over trickling units in countercurrent to the upwardly flowing cooling air. The radial main channels and the normally arranged auxiliary channels extend nearly over the total horizontal cross section of each V-shaped sector of the wet cooling section. A collecting reservoir for the water is provided at the bottom of these sectors.
The sectors for the dry cooling section have channels of substantially open cross section which are only at the circumference of the tower provided with substantially vertically extending heat-exchanger elements. The updraft for the cooling air for the wet cooling section as well as for the dry cooling section is produced by a ventilator arranged above the aforementioned sectors on a central column.
An essential disadvantage of this known construction consists in that the heat-exchanger elements of the dry cooling section are arranged on the circumference of the cooling tower. Such an arrangement will be susceptible to the influence of wind passsing around the cooling tower since during passing of wind around the cooling tower a greatly varying pressure profile will be formed on the circumference of the tower. The influence of the wind passing around the cooling tower is further increased by the radial separating walls between the sectors of the wet cooling section and the dry cooling section. Such separating walls are, however, absolutely necessary in this known cooling tower construction since otherwise the cooling surfaces of the dry cooling section may be wetted with contaminated water. In addition, the necessary radial separating walls evidently increase the production costs of such a cooling water considerably.
In this known construction it is also necessary to provide separate air inlet openings for the sectors of the wet cooling section as well as for the sectors of the dry cooling section. Such different air inlet openings are difficult to realize constructively and this is an additional considerable disadvantage of the known cooling tower construction. Furthermore, due to the alternating arrangement of sectors for the wet cooling section and sectors for the dry cooling section, the arrangement of the necessary conduits, especially for the dry cooling section, will be complicated and expensive. In addition, the collecting container for the water to be cooled in the wet cooling section will necessarily extend substantially over the whole cross section of the cooling tower, which likewise increases its production costs.